The present invention relates generally to a keyboard in an electronic device and, more particularly, to a double-sided keyboard having two keymats, or two sets of individual keys, located on both sides of the keyboard for entering information into an electronic device.
Man-machine interaction, in terms of user input, is of utmost importance in portable communication devices. Splitting up one single keyboard into two or more sub-keyboards is one of the ways to improve the efficient use of a communication device. For example, in a Nokia Communicator, the phone keyboard is used when the Communicator functions as a telephone and another separate QWERTY keyboard is used when the Communicator is used for other functions. As portable communication devices become smaller and more compact, the available space and volume for two or more sub-keyboards becomes more limited. One way to solve this limited space problem is to implement two keyboards on the two sides of the phone cover, which is also known as an active flip, or on the opposite sides of the device itself. Conventionally, each of the two keyboards on the same active flip, or the device itself, has a separate circuit board to allow the keys on each keyboard to enter information through their own activation devices on the respective circuit board. This type of double-sided keyboard is disclosed, for example, in U.S. Pat. No. 6,038,313 (Collins). Although this type of double-sided keyboard arrangement can save space, it is costly to produce. U.S. Pat. Nos. 5,715,524 and 5,742,894 (Jambhekar et al.) disclose a radio communication device, wherein a touch screen display is used to enter information when the device is in an opened position, and a depressible keypad is used when the device is in a closed position. When the device is in the closed position, part of the touch screen display is concealed behind the depressible keypad. The keys on the depressible keypad use the concealed portion of the touch screen display to enter information. While this type of multiple keyboard can save space and cost, it is only applicable for those devices that have a touch screen display.
It is desirable to provide a cost-effective method and apparatus for entering information using different keys on different sub-keyboards without the need of a touch screen display.
The first aspect of the present invention is a double-sided keyboard for entering information in an electronic device. The keyboard comprises:
a circuit board having a first side and an opposing second side;
a first keymat having a first plurality of keys located on the first side;
a second keymat having a second plurality of keys located on the second side; and
an activation mat having a plurality of activation sections located between the first keymat and the circuit board so as to allow the first and second keymats to activate the circuit board by pressing at least one of the keys in order to cause at least one of the electrically conductive sections to operatively engage with the circuit board for providing a signal indicative of the information for use in the electronic device.
Preferably, the circuit board includes a plurality of connection areas, and the activation sections include a plurality of dome-shaped contact pads, each of which is electrically conductive and located above one of the electrical connection areas, such that the signal is provided to the circuit board in response to the depressing of one of the keys, causing one of the contact pads to make contact with the respective connection area.
It is possible that some of the first plurality of keys share the same contact pads with some of the second plurality of keys.
It is possible that some of first plurality of keys and some of the second plurality of keys have their own contact pads.
It is possible to integrate part of the circuit board into the second keymat such that the connection areas are located on the second keymat and underneath the dome-shape contact pads.
It is possible that the connection areas include pressure sensing elements such that the signal is provided to the circuit board in response to depressing one of the keys, causing one of the activation sections to apply pressure to the respective connection area.
It is possible that the connection areas include capacitive sensing elements such that the signal is provided to the circuit board in response to depressing one of the keys, causing one of the action sections to affect the capacitance of the respective connection area.
When the electronic device has an active flip, it is preferable to implement the keyboard on the active flip such that the first plurality of keys can be accessed from one side of the active flip and the second plurality of keys can be accessed from the other side of the active flip.
Alternatively, the keyboard can be implemented on the body of the electronic device such that the first plurality of keys can be accessed from one side of the device body and the second plurality of keys can be accessed from the other side of the device body.
The second aspect of the present invention is a method of producing a double-sided keyboard for entering information in an electronic device. The method comprises the steps of:
providing a circuit board having a first side and an opposing second side;
providing an activation mat having a plurality of activation sections adjacent the first side of the keyboard;
providing a first keymat having a first plurality of keys adjacent the activation mat;
providing a second keymat having a second plurality of keys adjacent the second side of the keyboard so as to allow the first and second keymats to activate the circuit board by pressing at least one of the keys in order to cause at least one activation section to operatively connect to the circuit board for providing a signal indicative of the information for use in the electronic device.
The third aspect of the invention is a method of entering and using information in an electronic device. The method comprises the steps of:
pressing at least one of a first plurality of keys of a first keymat situated adjacent to a first side of an activation mat having a plurality of electrically conductive sections in order to cause at least one electrically conductive section of the activation mat to operatively connect to a circuit board having a first side and an opposing second side, wherein the first side of the circuit board situated adjacent a second side of the activation mat opposing the first side thereof, for providing a first signal, or
pressing at least one of a second plurality of keys situated adjacent to the second side of the circuit board in order to cause at least one electrically conductive section of the activation mat to operatively connect to the circuit board, for providing a second signal; and
using either the first signal or the second signal for performing a function related thereof in the electronic device.
The present invention will become apparent upon reading the description taken in conjunction with FIGS. 1a to 7b.